EL PASO, Texas (Border Report) – The migrant caravan that has been assembling in Southern Mexico for the past few weeks is ready to march north, Mexican media report.

At least 3,400 non-Mexican citizens who’ve petitioned for court writs to travel beyond the city of Tapachula near the border with Guatemala plan to set off at 6 a.m. Saturday with or without such authorization, Diaro del Sur reported.

Mexico’s National Migration Institute (INM) “has left us no alternative but to march toward the center of the country,” caravan organizer Irineo Mujica told the newspaper. “This march is for the freedom of thousands of migrants detained in this open-air prison called Tapachula.”

The activist told the newspaper he doesn’t plan to travel farther than Mexico City. “Our march is going to the center of (Mexico) so that Immigration hears from all the migrants stuck in the city,” he told Diario del Sur.

But migrants joining the caravan are intent on reaching the U.S. border. Jonathan, a citizen of Peru who arrived this week in Tapachula, told the newspaper he is part of a 1,500-strong WhatsApp group of South America intent on joining the caravan.

“I just crossed Guatemala, but I don’t want to stay here. I need to go to the northern border where there are other Peruvians, and they say things are better there than in Tapachula,” he told Diario del Sur.

The caravan consists of people from Haiti, Central and South America, the newspaper reported.